Editorial Type:
Article
Article Type:
Research Article

Model Wind over the Central and Southern California Coastal Ocean

Hsiao-ming Hsu National Center for Atmospheric Research,* Boulder, Colorado

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Lie-Yauw Oey Princeton University, Princeton, New Jersey

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Walter Johnson Minerals Management Service, Herndon, Virginia

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Clive Dorman Scripps Institution of Oceanography, La Jolla, California

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Richard Hodur Naval Research Laboratory, Monterey, California

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Print Publication:
01 May 2007
DOI:
https://doi.org/10.1175/MWR3389.1
Page(s):
1931–1944
Restricted access

Abstract

Recent studies have shown the importance of high-resolution wind in coastal ocean modeling. This paper tests the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) at the 9-, 27-, and 81-km grid resolutions in simulating wind off the central and southern California coasts, including the Santa Barbara Channel (SBC). The test period is March–May (1999) when the wind changes from its characteristics more typical of winter, to spring when strong gradients exist in the SBC. The model results were checked against wind station time series, Special Sensor Microwave Imager wind speeds, and the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis. The high-resolution (9-km grid) COAMPS wind shows expansion fans downwind of major capes where speed increases. The large-scale [O(100 km)] wind turns onshore in the Southern California Bight where both wind and wind stress curl weaken southward along the coast. The formation and evolution of the Catalina eddies are also simulated. These general features agree with observations. The turning appears to be the cumulative effect of synoptic cyclones shed downwind of Point Conception during periods of intense northerly wind. The turning and eddies are much weaker in the ECMWF reanalysis or the COAMPS field at the 81-km grid. Near the coast, observed small-scale (tens of kilometers) structures are reasonably reproduced by COAMPS at the 9-km grid. Results from the 9-km grid generally compare better with observations than the 27-km grid, suggesting that a more accurate model wind may be obtained at even higher resolution. However, in the SBC, simulated winds at both the 9- and 27-km grids show along-channel coherency during May, contrary to observations. The observed winds in the channel appear to be of small localized scales (≈<10 km) and would require an improved model grid and perhaps also boundary layer physics to simulate.

* The National Center for Atmospheric Research is sponsored by the National Science Foundation

Corresponding author address: Lie-Yauw Oey, AOS Program, Princeton University, Sayre Hall, Princeton, NJ 08544. Email: lyo@princeton.edu

Abstract

Recent studies have shown the importance of high-resolution wind in coastal ocean modeling. This paper tests the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) at the 9-, 27-, and 81-km grid resolutions in simulating wind off the central and southern California coasts, including the Santa Barbara Channel (SBC). The test period is March–May (1999) when the wind changes from its characteristics more typical of winter, to spring when strong gradients exist in the SBC. The model results were checked against wind station time series, Special Sensor Microwave Imager wind speeds, and the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis. The high-resolution (9-km grid) COAMPS wind shows expansion fans downwind of major capes where speed increases. The large-scale [O(100 km)] wind turns onshore in the Southern California Bight where both wind and wind stress curl weaken southward along the coast. The formation and evolution of the Catalina eddies are also simulated. These general features agree with observations. The turning appears to be the cumulative effect of synoptic cyclones shed downwind of Point Conception during periods of intense northerly wind. The turning and eddies are much weaker in the ECMWF reanalysis or the COAMPS field at the 81-km grid. Near the coast, observed small-scale (tens of kilometers) structures are reasonably reproduced by COAMPS at the 9-km grid. Results from the 9-km grid generally compare better with observations than the 27-km grid, suggesting that a more accurate model wind may be obtained at even higher resolution. However, in the SBC, simulated winds at both the 9- and 27-km grids show along-channel coherency during May, contrary to observations. The observed winds in the channel appear to be of small localized scales (≈<10 km) and would require an improved model grid and perhaps also boundary layer physics to simulate.

* The National Center for Atmospheric Research is sponsored by the National Science Foundation

Corresponding author address: Lie-Yauw Oey, AOS Program, Princeton University, Sayre Hall, Princeton, NJ 08544. Email: lyo@princeton.edu

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  • Allen, J. S., 1980: Models of wind-driven currents on the continental shelf. Annu. Rev. Fluid Mech., 12 , 389–433.

  • Beardsley, R. C., and S. J. Lentz, 1987: The Coastal Ocean Dynamics Experiment collection: An introduction. J. Geophys. Res., 92 , 1455–1463.

    • Search Google Scholar
    • Export Citation

  • Bosart, L. F., 1983: Analysis of a California Catalina eddy event. Mon. Wea. Rev., 111 , 1619–1633.

  • Brink, K. H., and R. D. Muench, 1986: Circulation in the Point Conception-Santa Barbara Channel region. J. Geophys. Res., 91 , 877–895.

    • Search Google Scholar
    • Export Citation

  • Burk, S. D., T. Haack, and R. M. Samelson, 1999: Mesoscale simulation of supercritical, subcritical, and transcritical flow along coastal topography. J. Atmos. Sci., 56 , 2780–2795.

    • Search Google Scholar
    • Export Citation

  • Caldwell, P. C., D. W. Suart, and K. H. Brink, 1986: Mesoscale wind variability near Point Conception, California during spring 1983. J. Climate Appl. Meteor., 25 , 1241–1254.

    • Search Google Scholar
    • Export Citation

  • Chen, S., and Coauthors, 2003: COAMPS™ version 3 model description: General theory and equations. Naval Research Laboratory, Monterey, CA, 143 pp.

  • Clark, J. H. E., 1994: The role of Kelvin waves in evolution of the Catalina eddy. Mon. Wea. Rev., 122 , 838–850.

  • Clark, J. H. E., and S. R. Dembek, 1991: The Catalina eddy event of July 1987: A coastally trapped mesoscale response to synoptic forcing. Mon. Wea. Rev., 119 , 1714–1735.

    • Search Google Scholar
    • Export Citation

  • Davis, C., S. Low-Nam, and C. Mass, 2000: Dynamics of a Catalina eddy revealed by numerical simulation. Mon. Wea. Rev., 128 , 2885–2904.

    • Search Google Scholar
    • Export Citation

  • Davis, R. E., 1976: Predictability of sea surface temperature and sea level pressure anomalies over the North Pacific Ocean. J. Phys. Oceanogr., 6 , 249–266.

    • Search Google Scholar
    • Export Citation

  • Dong, C., and L-Y. Oey, 2005: Sensitivity of coastal currents near Point Conception to forcing by three different winds: ECMWF, COAMPS, and blended SSM/I–ECMWF–Buoy winds. J. Phys. Oceanogr., 35 , 1229–1244.

    • Search Google Scholar
    • Export Citation

  • Dorman, C. E., 1985a: Evidence of Kelvin waves in California’s marine layer and related eddy generation. Mon. Wea. Rev., 113 , 827–839.

    • Search Google Scholar
    • Export Citation

  • Dorman, C. E., 1985b: Hydraulic control of the northern California marine layer. Eos, Trans. Amer. Geophys. Union, 66 , 914.

  • Dorman, C. E., and C. D. Winant, 1995: Buoy observations of the atmosphere along the west coast of the United States, 1981–1990. J. Geophys. Res., 100 , 16029–16044.

    • Search Google Scholar
    • Export Citation

  • Dorman, C. E., and C. D. Winant, 2000: The structure and variability of the marine atmosphere around the Santa Barbara Channel. Mon. Wea. Rev., 128 , 261–282.

    • Search Google Scholar
    • Export Citation

  • Doyle, J. D., 1997: The influence of mesoscale topography on a coastal jet and rainband. Mon. Wea. Rev., 125 , 1465–1488.

  • Haack, T., S. D. Burk, C. E. Dorman, and D. P. Rogers, 2001: Supercritical flow interaction within the Cape Blanco–Cape Mendocino orographic complex. Mon. Wea. Rev., 129 , 688–708.

    • Search Google Scholar
    • Export Citation

  • Harms, S., and C. D. Winant, 1998: Characteristic patterns of the circulation in the Santa Barbara Channel. J. Geophys. Res., 103C , 3041–3065.

    • Search Google Scholar
    • Export Citation

  • Hodur, R., 1997: The Naval Research Laboratory’s Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS). Mon. Wea. Rev., 125 , 1414–1430.

    • Search Google Scholar
    • Export Citation

  • Harshvardhan, and Randall, D., and T. Corsetti, 1987: A fast radiation parameterization for atmospheric circulation models. J. Geophys. Res., 92 , 1009–1016.

    • Search Google Scholar
    • Export Citation

  • Isaacson, E., and H. B. Keller, 1966: Analysis of Numerical Methods. John Wiley & Sons, 541 pp.

  • Kain, J. S., and J. M. Fritsch, 1990: A one-dimensional entraining/detraining plume model and its application in convective parameterization. J. Atmos. Sci., 47 , 2784–2802.

    • Search Google Scholar
    • Export Citation

  • Koračin, D., and C. E. Dorman, 2001: Marine atmospheric boundary layer divergence and clouds along California in June 1996. Mon. Wea. Rev., 129 , 2040–2056.

    • Search Google Scholar
    • Export Citation

  • Large, W. G., and S. Pond, 1981: Open ocean flux measurements in moderate to strong winds. J. Phys. Oceanogr., 11 , 324–336.

  • Mass, C. F., and M. D. Albright, 1989: Origin of the Catalina eddy. Mon. Wea. Rev., 117 , 2406–2436.

  • Munchow, A., 2000: Wind stress curl forcing of the coastal ocean near Point Conception, California. J. Phys. Oceanogr., 30 , 1265–1280.

    • Search Google Scholar
    • Export Citation

  • Oey, L-Y., 1996: Flow around a coastal bend: A model of the Santa Barbara Channel eddy. J. Geophys. Res., 101C , 16667–16682.

  • Oey, L-Y., 1999: A forcing mechanism for the poleward flow off the southern California coast. J. Geophys. Res., 104C , 13529–13539.

  • Oey, L-Y., D-P. Wang, T. Hayward, C. Winant, and M. Hendershott, 2001: Upwelling and cyclonic regimes of the near-surface circulation in the Santa Barbara Channel. J. Geophys. Res., 106C , 9213–9222.

    • Search Google Scholar
    • Export Citation

  • Oey, L-Y., C. Winant, E. Dever, W. Johnson, and D-P. Wang, 2004: A model of the near-surface circulation of the Santa Barbara Channel: Comparison with observations and dynamical interpretations. J. Phys. Oceanogr., 34 , 23–43.

    • Search Google Scholar
    • Export Citation

  • Perlin, N., R. M. Samelson, and D. B. Chelton, 2004: Scatterometer and model wind and wind stress in the Oregon–northern California coastal zone. Mon. Wea. Rev., 132 , 2110–2129.

    • Search Google Scholar
    • Export Citation

  • Persson, P. O. G., P. J. Neiman, and B. Walter, 2005: Contributions from California coastal-zone surface fluxes to heavy coastal precipitation: A CALJET case study during the strong El Niño of 1998. Mon. Wea. Rev., 133 , 1175–1198.

    • Search Google Scholar
    • Export Citation

  • Richtmyer, R. D., and K. W. Morton, 1957: Difference Methods for Initial-Value Problems. Interscience Publishers, 405 pp.

  • Rosenthal, J., 1968: A Catalina eddy. Mon. Wea. Rev., 96 , 742–743.

  • Rutledge, S. A., and P. V. Hobbs, 1983: The mesoscale and microscale structure of organization of clouds and precipitation in midlatitude cyclones. VIII: A model for the “seeder-feeder” process in warm–frontal rainbands. J. Atmos. Sci., 40 , 1185–1206.

    • Search Google Scholar
    • Export Citation

  • Samelson, R., 1992: Supercritical marine-layer flow along a smoothly varying coastline. J. Atmos. Sci., 49 , 1571–1584.

  • Samelson, R., and Coauthors, 2002: Wind stress forcing of the Oregon coastal ocean during the 1999 upwelling season. J. Geophys. Res., 107 .3034, doi:10.1029/2001JC000900.

    • Search Google Scholar
    • Export Citation

  • Skyllingstad, E. D., P. Barbour, and C. E. Dorman, 2001: The dynamics of northwest summer winds over the Santa Barbara Channel. Mon. Wea. Rev., 129 , 1042–1061.

    • Search Google Scholar
    • Export Citation

  • Therry, G., and P. LaCarrere, 1983: Improving the eddy kinetic energy model for planetary boundary layer description. Bound.-Layer Meteor., 25 , 63–88.

    • Search Google Scholar
    • Export Citation

  • Thompson, W. T., S. D. Burk, and J. Rosenthal, 1997: An investigation of the Catalina eddy. Mon. Wea. Rev., 125 , 1135–1146.

  • Ueyoshi, K., and J. O. Roads, 1993: Simulation and prediction of the Catalina eddy. Mon. Wea. Rev., 121 , 2975–3000.

  • Wakimoto, R., 1987: The Catalina eddy and its effect on pollution over Southern California. Mon. Wea. Rev., 115 , 837–855.

  • Wang, D-P., 1997: Effects of small-scale wind on coastal upwelling with application to Point Conception. J. Geophys. Res., 102C , 15555–15566.

    • Search Google Scholar
    • Export Citation

  • Wentz, F. J., 1997: A well-calibrated ocean algorithm for SSM/I. J. Geophys. Res., 102C , 8703–8718.

  • Wentz, F. J., and R. W. Spencer, 1998: SSM/I rain retrievals within a unified all-weather ocean algorithm. J. Atmos. Sci., 55 , 1613–1627.

    • Search Google Scholar
    • Export Citation

  • Winant, C. D., and C. E. Dorman, 1997: Seasonal patterns of surface wind stress and heat flux over the Southern California Bight. J. Geophys. Res., 102C , 5641–5653.

    • Search Google Scholar
    • Export Citation

  • Winant, C. D., R. Beardsley, C. Dorman, and C. Friehe, 1988: The marine layer off northern California: An example of supercritical channel flow. J. Atmos. Sci., 45 , 3588–3605.

    • Search Google Scholar
    • Export Citation
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